Absorbent core having tube-shaped swelling chamber

An absorbent core comprising absorbent material disposed in an absorbent material deposition area and enclosed in a core wrap, wherein the core wrap comprises a liquid permeable substrate layer and the absorbent material comprises from about 87% to about 100% of superabsorbent polymer by weight of the absorbent material, the absorbent core further comprising a tube-shaped swelling chamber, the tube-shaped swelling chamber having a length to width aspect ratio of less than or equal to about 5:1;

• wherein the area of the core is at least twice the area of the swelling chamber, and the core contains a water responsive immobilizing agent to immobilize the superabsorbent polymer prior to water insult;
• and
• wherein the tube-shaped swelling chamber is a portion of the absorbent core containing superabsorbent polymer that is delimited by a plurality of continuous permanent seals that each join together a top substrate layer and a bottom substrate layer of the core wrap and prevent superabsorbent polymer from moving across the seals, wherein at least two continuous permanent seals are longitudinally-extending and void of absorbent material wherein the chamber comprises a first chamber end at a first longitudinal position and a second chamber end at a second longitudinal position, wherein the first chamber end of the tube-shaped swelling chamber is closed by joining two or more of the continuous permanent seals together at the first chamber end and the second chamber end comprises an open end such that the plurality of continuous permanent seals are not joined to one another at the second longitudinal position, and
• wherein at the open end, at least one of the two or more of the continuous permanent seals each extend to a longitudinal edge of the absorbent material deposition area.